CVE-2026-58027 QueryAbuseFilter API can be used to see the hit count of private filters, which is hidden in the UI

Medium 5.3 Published 1 Jul 2026 Updated 1 Jul 2026

Attackers can use the QueryAbuseFilter API to view hit counts of private filters, exposing sensitive data hidden from the UI.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Over the internet
Victim action needed: Not needed
Fix: Available

What is CVE-2026-58027?

CVE-2026-58027 is a medium-severity vulnerability in Mediawiki Mediawiki, published on 1 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

Exposure of Sensitive Information to an Unauthorized Actor vulnerability in Wikimedia Foundation AbuseFilter.

This vulnerability is associated with program files includes/Api/QueryAbuseFilters.Php.

This issue affects AbuseFilter: from * before 1.46.0, 1.45.4, 1.44.6, 1.43.9.

Weakness: CWE-200

Which versions are affected by CVE-2026-58027?

It affects 1 product.

Products include Mediawiki Mediawiki.

How do I fix CVE-2026-58027?

Upgrade to a fixed version.

Is CVE-2026-58027 being exploited?

There is no known exploitation of CVE-2026-58027 in the wild and no public exploit code.

All Mediawiki Mediawiki vulnerabilities

Sources

Also known as DEBIAN-CVE-2026-58027, GHSA-xf4f-w4h8-w7rr, MINI-8f7g-qvvj-5mgm, MINI-g8jf-mvwq-685w, MINI-pg94-jcx4-q35g, UBUNTU-CVE-2026-58027.